Modes in 2-D buried optical waveguide with asymmetric graded refractive index profile

A dielectric waveguide, whose guiding region is located beneath the substrate surface, will be a useful configuration to connect optical functional devices fabricated in the same substrate. A convenient refractive index profile, which is based on the Morse potential function and is similar to that which is observed in practically fabricated optical waveguides, is introduced in order to study the propagation characteristics of the 2-D buried optical waveguide.